On the eigenvalue and eigenvector derivatives of a general matrix

The existence of differentiable eigenvalues and eigenvectors for a general matrix is addressed. The eigenspace which contains differentiable eigenvectors is determined and computed by using the concept of subspace intersection in conjunction with the singular value decomposition algorithm. The differentiable eigenvectors associated with repeated eigenvalues should be simultaneously the eigenvectors of the general matrix and its corresponding sensitivity matrix. Furthermore, the derivatives for differentiable eigenvectors associated with repeated eigenvalues can be computed using higher order derivatives of the matrix, whereas the corresponding eigenvalue derivatives are the eigenvalues of the sensitivity matrix

IMPROVING THE STUDENTS’ READING SKILL THROUGH TRANSLATION METHOD

The aims of this research are to find out how the implementation of translation can improve the students’ reading skill and how the students’ responses to the use of translation method in the teaching and learning process. This research is a classroom action research. The participant is 39 students. The research instrument used is in the form of observation checklist, test, and questioners. The finding of the research shows that the implementation of translation improves the students’ reading skill in the teaching process and the test result. The result of evaluation which carried out in end of the cycle I obtained that the lowest score is 40 and the highest score is 82 then the average score is 58.1, cycle II gets the lowest score is 50 and the highest score is 85 then the average score is 60,9, and cycle III get the lowest score is 60 and the highest score is 85 and the average score is 65.8. Therefore, it can be concluded that the translation method can improve the students’ reading skill of grade VII D of MTs. Muhammadiyah Yogyakarta and the students’ responses are positive when the teacher applied translation method in teaching and learning process

Self-consistent approach for the quantum confined Stark effect in shallow quantum wells

A computationally efficient, self-consistent complex scaling approach to calculating characteristics of excitons in an external electric field in quantum wells is introduced. The method allows one to extract the resonance position as well as the field-induced broadening for the exciton resonance. For the case of strong confinement the trial function is represented in factorized form. The corresponding coupled self-consistent equations, which include the effective complex potentials, are obtained. The method is applied to the shallow quantum well. It is shown that in this case the real part of the effective exciton potential is insensitive to changes of external electric field up to the ionization threshold, while the imaginary part has non-analytical field dependence and small for moderate electric fields. This allows one to express the exciton quasi-energy at some field through the renormalized expression for the zero-field bound state.Comment: 13 pages, RevTeX4, 6 figure

Deep Learning Enabled Semantic Communication Systems

Recently, deep learned enabled end-to-end (E2E) communication systems have been developed to merge all physical layer blocks in the traditional communication systems, which make joint transceiver optimization possible. Powered by deep learning, natural language processing (NLP) has achieved great success in analyzing and understanding large amounts of language texts. Inspired by research results in both areas, we aim to providing a new view on communication systems from the semantic level. Particularly, we propose a deep learning based semantic communication system, named DeepSC, for text transmission. Based on the Transformer, the DeepSC aims at maximizing the system capacity and minimizing the semantic errors by recovering the meaning of sentences, rather than bit- or symbol-errors in traditional communications. Moreover, transfer learning is used to ensure the DeepSC applicable to different communication environments and to accelerate the model training process. To justify the performance of semantic communications accurately, we also initialize a new metric, named sentence similarity. Compared with the traditional communication system without considering semantic information exchange, the proposed DeepSC is more robust to channel variation and is able to achieve better performance, especially in the low signal-to-noise (SNR) regime, as demonstrated by the extensive simulation results.Comment: 13 pages, Journal, accepted by IEEE TS

Reduced order models for control of fluids using the Eigensystem Realization Algorithm

In feedback flow control, one of the challenges is to develop mathematical models that describe the fluid physics relevant to the task at hand, while neglecting irrelevant details of the flow in order to remain computationally tractable. A number of techniques are presently used to develop such reduced-order models, such as proper orthogonal decomposition (POD), and approximate snapshot-based balanced truncation, also known as balanced POD. Each method has its strengths and weaknesses: for instance, POD models can behave unpredictably and perform poorly, but they can be computed directly from experimental data; approximate balanced truncation often produces vastly superior models to POD, but requires data from adjoint simulations, and thus cannot be applied to experimental data. In this paper, we show that using the Eigensystem Realization Algorithm (ERA) \citep{JuPa-85}, one can theoretically obtain exactly the same reduced order models as by balanced POD. Moreover, the models can be obtained directly from experimental data, without the use of adjoint information. The algorithm can also substantially improve computational efficiency when forming reduced-order models from simulation data. If adjoint information is available, then balanced POD has some advantages over ERA: for instance, it produces modes that are useful for multiple purposes, and the method has been generalized to unstable systems. We also present a modified ERA procedure that produces modes without adjoint information, but for this procedure, the resulting models are not balanced, and do not perform as well in examples. We present a detailed comparison of the methods, and illustrate them on an example of the flow past an inclined flat plate at a low Reynolds number.Comment: 22 pages, 7 figure

DATACRACY IN BUILDING MELIKAN VILLAGE, EFFORTS OUT OF EXTREME POVERTY

As one of the villages that fall into the category of extreme poor, Melikan Village in Klaten Regency must start using data in planning development. This study aims to explore how the Melikan Village Government utilizes the SDG's Village data in preparing development plans. The method used in this research is qualitative with an interpretative approach. The informants selected were the Village Head, Village Secretary, Heads of Affairs and Section Heads, BPD Chairs and Members, youth leaders and community leaders. The results showed that the Melikan Village Government did not know from where the data sources used by the supra-village government in determining the village poverty level came from. Even the village head questioned the source of the data used to determine Melikan as a village with an extreme category. The real conditions in Melikan Village do not show any indicators of extreme poverty. In development planning, Melikan Village has not been based on data because it prioritizes the village deliberation process. Melikan Village conducts the SDG's Village data collection process which can be used as a basis for future development planning by prioritizing the first goal of SDG's Desa, namely a village without poverty

GaSb on GaAs interfacial misfit solar cells

The GaAs/GaSb interface misfit design can achieve comparable efficiency to conventional inverted metamorphic multijunction cells at up to 30% cost reduction. In this pre-liminary work, GaSb single junctions were grown via molecular beam epitaxy on both GaSb and GaAs substrates to compare and fine tune the interfacial misfit growth process. Current vs voltage results show that the best homo-epitaxial cell achieved 5.2% under 35-sun concentration. TEM did not reveal any threading dislocations in the hetero-epitaxial cells, however, device results indicated higher non-radiative recombination than expected, likely due to unpassivated surface states. Improvements to cell processing will be explored and more characterization is planned to determine the cause of degraded hetero-epitaxial cell performance

GaSb Thermophotovoltaic Cells Grown on GaAs by Molecular Beam Epitaxy Using Interfacial Misfit Arrays

There exists a long-term need for foreign substrates on which to grow GaSb-based optoelectronic devices. We address this need by using interfacial misfit arrays to grow GaSb-based thermophotovoltaic cells directly on GaAs (001) substrates and demonstrate promising performance. We compare these cells to control devices grown on GaSb substrates to assess device properties and material quality. The room temperature dark current densities show similar characteristics for both cells on GaAs and on GaSb. Under solar simulation the cells on GaAs exhibit an open-circuit voltage of 0.121 V and a short-circuit current density of 15.5 mA/cm2. In addition, the cells on GaAs substrates maintain 10% difference in spectral response to those of the control cells over a large range of wavelengths. While the cells on GaSb substrates in general offer better performance than the cells on GaAs substrates, the cost-savings and scalability offered by GaAs substrates could potentially outweigh the reduction in performance. By further optimizing GaSb buffer growth on GaAs substrates, Sb-based compound semiconductors grown on GaAs substrates with similar performance to devices grown directly on GaSb substrates could be realized

Promoting positive development among refugee adolescents

Of the estimated 35.3 million refugees around the world (UNHCR, Figures at a Glance, 2022), approximately 50% are children under the age of 18. Refugee adolescents represent a unique group as they navigate developmental tasks in an unstable and often threatening environment or in resettlement contexts in which they often face marginalization. In addition to physiological, social, and psychological changes that mark adolescence, refugee youth often face traumatic experiences, acculturative stress, discrimination, and a lack of basic resources. In this consensus statement, we examine research on refugee adolescents' developmental tasks, acculturative tasks, and psychological adjustment using Suárez-Orozco and colleague's integrative risk and resilience model for immigrant-origin children and youth proposed by Suárez-Orozco et al. Finally, we discuss recommendations-moving from proximal to more distal contexts